pabkhubst



(No Model.) 3 Sheets-Sheet 1.

DPARKHURST.

Y HEAD BLOCK FOR SAW MILLS. No. 257,060. Patented Apr.25,1882.

(No Model.) 3 Sheets-Sheet D. PARKHULST.

BLAD BLOCK FOL SAW MILLS.

No. 257,060. Patented Apr.25, 1882.

J L D I (No Model.)

3 Sheets--Sheet 3. D. PARKHURST. l

HEAD BLOCK FOR SAW MILLS.

Patented Apr. 25, 1882.

N. PUERS. mamumgnpmr. washington D.

pawl in any one of three positions.

UNITED STATES vPATENT OFFICE.

DARIUS PARKHURST, OF ST. LOUIS, MISSOURI, ASSIGNOR OF ONE-HALF TO GEO.H. KNIGHT, OF SAME PLACE. 4

VHEAD-BLOCK FOR SAW-MILLS.

SPECIFICATION forming part of Letters `Patent No. 257,060, dated April,25, 1882.

(No model.)

To all whom it may concern Be it known that I, DAEIUs PARKHURs'r, of thecit) of St. Louis, in the State of Missouri, have invented a certain newand useful Iniprovement in Saw-Mill Head-Blocks, of which the followingis a full, clear, and exact description, reiei-enee being had to theaccompanying drawings, forming part of this specification.

My invention relatesto a head-block which can be readily attached to anycarriage; and my invention consists broadly in combining the index, theratchet,fand the brake-wheels in one, as clearly set forth hereinafter,and shown in the drawings, in which- Figure 1 is a perspective view,showing the frame ofthe block or set-works secured to the timbers of acarriage, and showing one ot' the knees. Fig. 2 is a side view of partof the operating-lever and the 'device for keeping the Fig. 3 is a topview of the block, and Fig. 4. is a side elevation of the saine. Fig. 5is a side elevation of partofthe wheel, showing the ratchetteeth on theunder side of the rim. Fig. 6 is a detail view, showing a portion of thewheel, the index, and a portion of the shaft. VFig. 7 is a detailviewofthe upper end of the index, showing the rib which engages with theindex-teeth. Fig. 8 is a view of the wheel, and adjacent parts from theinner side.

A represents the frame, which is connected to the carriage-timberssubstantially as shown in Fig. l.

B is the main shaft, which has journal-bearings in suitable boxes,-O O,secured tothe frame. Keyed to this Vshaft is a bevel cog-wheel, D,engaging with a similar Wheel, E, keyed to the end of the counter-,shaftF, having journalbearing in boxes G G, secured to the frame. Ohnhtheshaft Fis the Wheel` H, lever I, index .IQ/collar K', and band-wheel L.(See Fig. 1.) The lever I and index J are loose upon the shaft, so thatthey do not necessarily turn with it. The wheel H has spokes M and arim, N, with a flange, M'. On the outer vertical face of the rim N areindex-teeth N8. The index J is located on the outer side of the wheel,and it has a rib, o, (see Figs. 6 and 7,)`for engaging with theindex-teeth. The index terminates in a handle for moving it, whendesired,

and its lower portion is made thin, so as to act as a spring to keep therib 0 in engagement with the teeth, and at the same time to allow it tobe disengaged therefrom, when desired, by a side strain. The collar K isbetween the index and the journal-box of that end ofthe shatt, and itsoffice is to keep the index up close against the wheel.

Q is an arm secured to the frame A infront 6o of the wheel.l It has aninclined side` against which the index strikes, and it also has notchesR R', which engage with the rib 0 0f the index, as hereinafter setforth. y

Secured to the frame behind the wheel is a safety-cam, S, its purposebeing to disengage the index from the wheel to avoid all danger ofbreaking the teeth should the wheel be turned backward too far-as, forinstance, in rolling on a heavy log, when it strikes the knees theirtendency to retreat `will cause the backward rotation'of the shaft B,which would act in turn on the counter-shaft F and consequently on thewheel H and it is desirable that the parts should thus give way to aheavy sudden strain of this kind upon the knees,for it avoids danger ofbreakage of the parts. By applying the brake to the wheel the parts willbe keptfrom moving backward too far.

The rim N outside the ange M', is made 30 smooth and forms thebearing-surface for the friction-strap brake T, connected by one end tothe frame A, (see Fig. 4,) and by the other end to the inner end of thelever U, which is fulcrumed to a standard, U', secured to and 85extending upward from the frame A. The lever is notched or serrated onits upper edge or face so as tobe engaged and held to any adjustment bya pawl or dog, V, pivoted t0 the frame. (See Figs. 3 and 4.) 90

On the inside of the rim N are ratchet-teeth N', which may be engaged byeither member of a reversible pawl, I', pivoted to the lever I, and thusthe wheel can be turned by the lever I in either direction, andconsequently the Q5 shafts F and B, which cause the backward or forwardmovement of the knees. The pawl is reversed by means of the handle N3. Y

To keep either member of thereversiblepawl in contact with the wheel, orto keep the pawl out ot'engagement with the wheel altogether, I employthe following device.

N3 (see Fig. 2) is a block rigidly secured to or forming a part of thesame rivet or bolt as vthe pawl on the other side of the handle, and

having a notch in the center of its lower end. Against this lower end ofthe block bears a V-shaped cam, N4, whose stem N5 works in lugs NG onlthe lever.

N'l is a spiral spring surrounding the stem of the cam between thelugs,which holds the cam in contact with the block. When the pawl is out ofengagement with the wheel the cam rests in the notch of the block, andwhen either member of the pawl is in engagement with the wheel theopposite lower edge of the block bears against the inclined face of thecam, (see dotted lines, Fig. 2..)

W is a guide-bar for the lateral support of the lever. It is secured tothe frame by its opposite ends,'and on it is a stop, W', which may beused to limit the forward movement of the lever.

'X is a ygage-bar secured to the fram'e, having a stop, V, with aset-screw, Z'. This bar is marked oft' into inches and parts thereof.

- The operation of the'machine is as follows: Before rolling a log ontothe carriage the pawl is thrown out of engagement with the wheel, andthe index is also thrown out of engagement with the wheel by engaging itwith notch R of the arm Q, and the brake applied. Then when the logstrikes the knees they will be allowed to give slightly, together withthe other parts, asand for the purpose set forth. The pawl is thenthrown into engagement with the wheel and the parts l turned forward,which moves the log up to the saws; or, if the logis to be moved fromthe saws, the other member of the pawl is thrown into engagement withthe wheel, and the parts moved backward,(thebrakeofcourse having beenremoved, or partially so, as desired.) Generally when a log is beingslabbed which does not require a careful adjustment it would bequickerto move it by means ofthe hand-wheel L, which isvkeyed. to theouter end of the shaft F for that purpose. When the hand-wheel is thusused the pawl andindex are thrown out ofengagement with the wheel.

l will now suppose that the log has been slabbed andemoved up tothesaws, and that it is desired to cut a one-inch board therefrom.

The stop Y is iirst moved to the numeral l on'` the gage-bar and securedthere by the set-screw, when the index, being in front of the stop, isbrought back until it comes against the stop, when Vit is engaged withthe teeth'of the wheel. Next, the wheel is moved forward until the ribon the index engages with the notch R in the arm Q, which stops theforward movement of the wheel, for it will still be engaged by theindex. This will movethe log toward the saws one inch, and the operationcan be repeated as often as desired; and if it is desired to cut athicker or thinner board the stop Y would be accordingly adjusted on thescale-bar and the index movedup to it each time.

that in the drawing back the lever each click of 8o the pawl willrepresent such movement, and thus the distance may be measured by theear.

' The brake is-not only useful when the log.

is being rolled on, as described, but it is also useful at any othertime to prevent a return movement of the knees under pressure of thelog. Its character allows its force to be varied at will, as can beplainly seen.

Having thus described my invention, the following is what I claim as newtherein and desire to secure by Letters Patent:

l. In a head-block for saw-mills, the com bined index, ratchet, andbrake-wheel, in combination with suitable lever,index, and brake, as setforth.

2. In ahead-block for saw-mills, the wheel H, with rim `\N,ratchet-teeth N', and indexteeth N8, in combination with arm J and leverI, carrying` reversible pawl, substantially as and for the purpose setforth.

3. In a head-block for sawmills, the index, ratchet, and brake-wheelcombined in one, in combination with alever, I, having reversible pawlI,an index, J, and a brake, T, to receive the rebound, all substantiallyas specified.

4. The combination of wheel H, leverI, provided with pawlI, brake T,index J, and arm Q, with notchesRR, substantially as specified.

5. In a head-block for saw-mills, the cam S, in combination with thewheel H and index J, secured to the frame A for the purpose set forth.`

6. In a head-block for saw-mills, the wheelV H, lever I, provided with apawl, I', arm Q, and index J, the latter being made thin so as to act asa spring, and having a rib, o, for engaging with the teeth of the wheeland with notches ofthe arm Qfall substantially as and for the purposeset forth.

7. In a head-block for saw-mills, the combination of wheel H, lever I inrear, reversible pawl I', index J in front, shaft T, arm Q, cam S, brakeT beneath the wheel, lever U, pawl V, scale-bar X, provided with stop Y,all supported by the frame A, andthe shaft F, engaging with the mainshaft B, all substantially as and for the purpose set forth.

DARIS PARKH URST.

Witnesses:

GEO. H. KNIGHT, CHARLES PrcxLEs.

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